1. Field of the Invention
This invention relates generally to an eye treatment system, and more specifically to an eye treatment system utilizing multiple pumps.
2. Description of the Related Art
Volumetric and vacuum pumps are used for removing fluid and other material from a surgical site. For example, in ophthalmic surgical systems, a peristaltic pump may be used to precisely regulate the flow of fluid to and from the eye during a cataract, vitrectomy, or other surgical procedure. Alternatively, vacuum pumps, such as Venturi pumps or rotary vane pumps, may be preferred by some surgeon or offer advantages for certain types of procedures compared to volumetric pumps. In some cases, it may be desirable to offer both types of pumps in a single system. Examples of such configurations are discussed in U.S. Pat. No. 5,195,960, U.S. Patent Application No. 2003/0108429, and PCT Patent Application Publication WO 93/17729, all of which are herein incorporated by reference.
Surgical systems utilizing vacuum pumps are generally based on the flow of a gas or other fluid. Consequently, the vacuum source must generally be isolated from fluids being removed from the surgical site. A holding tank may be used to provide this function and to provide a location where fluid and other material removed from the surgical site can be stored. To provide isolation, the holding tank may be configured with a first port at or near the top of the tank that is coupled to the vacuum source and a second port at or near the bottom of the tank that is connected to an aspiration line from the surgical site.
In some instances, it is desirable to incorporate at least portions of the pumping system into a disposable or reusable cassette. In the case of ophthalmic surgical systems, the cassette interfaces with a surgical console and couples the console to a handpiece with a probe that is inserted into the eye. The cassette generally contains tubing or fluid channels for coupling the handpiece to irrigation and aspiration sources, as well as for coupling to a volumetric pump head located inside the surgical console. In addition, the cassette may contain a holding tank that is coupled to a vacuum source that is also located inside the surgical console.
In order to provide a cassette having relatively small, inexpensive form and to maintain tight control of the vacuum pressure provided to the handpiece, the holding tank of the cassette is also preferably small. The small size of the holding tank generally necessitates periodic draining of the holding tank into a collection bag that may be directly attached to the body of the cassette.
Consequently, there is a need to provide cassette designs that allow for several pumps to be coupled together in a package that is relatively small and that is able to be easily and quickly installed prior to a surgical procedure.